Slide Mechanism

ABSTRACT

A slide mechanism for a piece of furniture having a slidable member, the slide mechanism comprising (a) a fixed slide rail; (b) a rebate which in use receives the fixed slide rail; (c) first biasing means to resist engagement of the fixed slide rail with the rebate; and (d) a second biasing means to resist freefall of the slidable member; wherein in use the slidable member is moved from a first, fully raised position to a second, fully lowered position by exerting force on the first biasing means such that the slide rail is brought into engagement with the rebate, subsequent vertical movement of the slidable member being counterbalanced by the second biasing means.

FIELD OF THE INVENTION

The present invention relates to a slide mechanism for furniture. Moreparticularly it relates to a slide mechanism for furniture having apanel, wall or similar component that is vertically slidable relative tothe other parts of the furniture. For example, the slide mechanism ofthe present invention may be suitable for furniture such as a child'scot having one or more sides that can be moved vertically relative tothe rest of the cot.

BACKGROUND OF THE INVENTION

In this specification where a document, act or item of knowledge isreferred to or discussed, this reference or discussion is not anadmission that the document, act or item of knowledge or any combinationthereof was at the priority date publicly available, known to thepublic, part of the common general knowledge, or known to be relevant toan attempt to solve any problem with which this specification isconcerned.

Whilst the following description relates to a child's cot, it will beappreciated that the invention is not so limited and could relate toother furniture such as cribs, or hospital beds having a panel, railingor other generally planar side member that needs to be moved vertically.

Children's cots are common furniture items in homes where small childrenlive. Typically a cot is a simple, small, rectangular bed having 2 fixedends, and 2 high sides, usually enclosing a mattress or other bedding.The sides and ends are designed to stop a child falling or climbing fromthe cot. The sides may be solid, but more typically they are of openconstruction so the child can see out. Typically the sides consist of arectangular frame supporting a series of vertical wooden rods that forma railing.

The sides of the cot must be deep enough to ensure the child cannot fallor climb out, however if the sides are deep it may be difficult for anadult to lift the child in and out of the cot. Accordingly it is commonfor one of the sides of the cot to be moved out of position in order toallow access to the interior of the cot. Typically the side is able tobe vertically slid into and out of position.

Although cots are freely available and widely used, almost all cotssuffer from a range of deficiencies related to the mechanism that allowsthe side to be moved. Typical safety issues are described in Australian& New Zealand cot standard, Cots for household use—Safety requirements(AS/NZ 2172:1995). Some cots fail to satisfy the requirements of thesafety standard. For example, one of the problems associated with cotsof the prior art is that the mechanism by which the side slides into andout of position has projections or recesses that could be used as afoothold by a child trying to climb out of the cot. Some sliding sidemechanisms do not satisfy the safety standard because they have gaps inwhich a child can trap a finger or toe. It is also important that themechanism for the sliding side automatically locks in position andcannot be released by a child who pushes or falls against it, yet theside must be quickly and easily operated by an adult.

One improved type of cot is described in International patentapplication PCT/AU2004/001441. The cot has a horizontal base forsupporting a mattress, and four sides, at least one which can bemanually moved between a first, fully raised position and a second fullylowered position. One of the advantages of the invention taught anddisclosed in this application is that the mechanism is fully enclosedand the latching means is not able to be accessed by a child oraccidentally released. This type of cot relies on an operator manuallymoving the cot side between the first, fully raised and second, fullylowered position. This can be difficult to manage for some operators,particularly if the side is very heavy or if the movement needs to becarried out repeatedly. Furthermore it is possible for the side to fallfrom the fully raised position to the fully lowered position if, forexample the operator loses their grip on the side.

Clearly, addressing the requirements of safety standards for cots hasmany practical, commercial and social advantages provided they result ina product that is convenient and practical to use. Optimally such aproduct will have one or more convenient features such as being simpleand robust in its mechanical makeup, reliably, low maintenance needs andmanufacturing tolerances that make it relatively straightforward tomanufacture.

It has now been found that a slide mechanism can be provided that meetssafety standards and is easier and more convenient to use thanmechanisms of the prior art.

SUMMARY OF THE INVENTION

The present invention therefore provides a slide mechanism for a pieceof furniture having a slidable member, the slide mechanism comprising:

(a) a fixed slide rail;(b) a rebate which in use receives the fixed slide rail;(c) a first biasing means to resist engagement of the fixed slide railwith the rebate; and(d) a second biasing means to resist freefall of the slidable member;wherein in use the slidable member is moved from a first, fully raisedposition to a second, fully lowered position by exerting force on thefirst biasing means such that the slide rail is brought into engagementwith the rebate, subsequent vertical movement of the slidable memberbeing counterbalanced by the second biasing means.

Typically the first biasing means is a spring that exerts force in agenerally horizontal direction such that an operator needs to push onthe slidable member to counter the horizontal force, thus bringing thefixed slide rail into engagement with the rebate.

Typically the second biasing means is a spring such as a coil spring, aspiral balance tube (of the type used for sash windows) or a gas-strutthat counterbalances any downward force on the slidable member. Forexample the second biasing means may resist the effect of gravity sothat the slidable member will not freefall if, for example, the operatorloses their grip on the slidable member while moving it between thefirst and second positions. Typically the degree of bias on the secondbiasing means can be adjusted to provide a desired degree ofcounterbalance to resist gravity or the force exerted by an operatorlowering the slidable member.

For example, the degree of bias could be adjusted to allow the slidablemember to lower under its own weight, at a suitably slow rate.Alternatively the degree of bias can be se such that the slidable membercan auto-rise from the second, fully lowered position to the first,fully raised position. This is a preferred failsafe position for manyapplications, such as a child's cot. If the slide mechanism fails, theslidable member remains or moves to the fully raised position, keepingthe child safely inside. By contrast, slidable sides on cots of theprior art typically fail to the fully lowered open position such that achild can fall out of the cot.

Typically the slidable member is generally planar. For example theslidable member may be a panel or a frame having vertical or horizontalbars to form a railing. With reference to a cot, the slidable member maycomprise a square or rectangular side which can be moved between afirst, fully raised position and a second, fully lowered position. In apreferred embodiment, both sides of the cot have slidable members thatuse a slide mechanism according to the present invention.

Preferably the rebate is located in a vertical edge of the slidablemember. Preferably the first and second biasing means are also concealedin a vertical edge of the slidable member. The rebate and/or biasingmeans are thus protected from interference or damage and the appearanceof the furniture is enhanced by concealment of the working parts of theslide mechanism. More importantly, concealment of the rebate and/orbiasing means avoids protrusions and recesses which may presentfootholds for a child in the cot. Concealment also avoids the risk of achild catching their fingers or toes in the mechanism.

When the furniture item is a cot, typically the fixed slide rail ispermanently attached to the cot frame or ends by permanent mechanicalfasteners. The slide rail may be continuous or discontinuous, comprisingtwo or more rail parts. Preferably, when the cot side is in the fullyraised position, the vertical edges abut the fixed ends of the cot (thatis, the headboard and footboard). Preferably, when the cot side is inthe fully lowered position, the vertical edges abut the fixed ends ofthe cot, and/or the cot legs.

Typically a sliding plate or similar mechanism is movably attached tothe sliding rail and fixed to the ends of the slidable member such thatwhen the rebate of the slidable member engages the fixed slide rail, theslidable member is free to move vertically but not horizontally withrespect to the fixed ends of the cot.

Preferably, in use the fixed slide rail is also concealed within theslidable member. Typically the fixed slide rail is concealedirrespective of whether the slidable member is in the first position,the second position or any position between these two extremes. Thisfurther reduces hazards and improves cot safety.

In a preferred embodiment, when the slidable member is a side for a cot,it may be moved between a first position, in which it is fully raisedand a second position in which it is fully lowered. In the fully raisedposition, it provides a barrier to a child falling or climbing out ofthe cot. In the fully raised position it cannot be pushed downwardmerely by the application of downward vertical force; it may only bemoved from the fully raised condition by inward pressure on at least oneof the lower corners of the side in order to overcome the resistance ofthe first biasing means. The pressure thus bring the rebate intoengagement with the fixed slide rail. The sliding side is then free tomove vertically downward against the counterbalancing force of thesecond biasing means. The sliding side may then be lowered until itsdescent is halted by some convenient means. For example, it may behalted by a stop incorporated in the slide rail or a separate buffer,rest or détente. Fully lowering the side provide easy access for anadult wishing to put a child in the cot or lift them out of the cot.

Typically the counterbalancing force of the second biasing means isadjustable. For example, the biasing means may be adjusted to allow thesliding side to slowly slide downward along the fixed slide rail underits own weight and the force of gravity. Alternatively the secondbiasing means can be adjusted to slowly descend under the combinedeffects of gravity and downward force exerted by an operator.

From the fully lowered position the side can be manually lifted to thefully raised position with the assistance of the second biasing means.Alternatively, the second biasing means can be adjusted to provide allthe vertically upward force required to raise the sliding side withoutthe application of manual force. When the slidable member reaches thefully raised position at the upper end of the slide rail, the firstbiasing means pushes the rebate out of engagement with the slide rail.The slidable means cannot move downwards when it is out of engagementwith the slide rail, thus there cannot be any non-deliberate downwardmovement of the slidable member.

The present invention may additionally include one or more latches. Forexample the sliding side may be latched in the first, fully raisedposition or the second, fully lowered position or optionally, anyposition between the first and second positions. The latch couldcomprise any convenient mechanism, such as a pawl-type mechanism. In aparticularly preferred embodiment the pawl is in the form of ahorizontal element removably attached to the slidable member, thehorizontal element sliding in and out of engagement with a verticalprotrusion on the headboard of the cot.

Alternatively the latching mechanism may comprise multiple mechanicallinkage mechanisms that perform a pawl action of engagement ordisengagement. The latch may be actuated by manual or automatic means.The automatic means may be remotely actuable, such as by radiofrequency,or other frequency waves tuned to an electromechanical actuator.

In a particularly preferred embodiment the present invention includes amanually operated latch mechanism, such as a foot operated latchmechanism. For example the latch may comprise a footplate, attached to arod located on the underside of the sliding side that holds the slidingside in second, fully lowered position countering any force exerted bythe second biasing means. Pressure exerted on the footplate rotates therod out of engagement with a retaining means, such as, for example, theend of the fixed sliding rail. The force exerted by the second biasingmeans may then allow the sliding side to slowly rise vertically until itreaches the first, fully raised position unless it is latchedintermediate the first and second positions

The present invention has the added advantage of allowing relativelyeasy removal of the slidable member. This permits ready removal of thebedding, including the mattress, for cleaning or replacement.Furthermore the present invention provides an easy means for convertinga cot to a cot bed and thus allowing the one piece of furniture to beused for a baby, then modified for use as the baby becomes a toddler.Specifically, the sliding side and slide rail can be readily removed intheir entirety using a single tool, such as a screwdriver. This leavesframe of the cot, such as the head board and foot board with little orno sign that they ever supported fittings and fixtures.

DESCRIPTION OF THE DRAWINGS

The invention will now be further explained and illustrated by referenceto the accompanying drawings in which:

FIG. 1 is a perspective view of a portion of a child's cot, cut-away inpart to show the incorporation of the slide mechanism of the presentinvention;

FIG. 2 is an enlarged view of the lower part of the slide mechanismdepicted in FIG. 1;

FIG. 3 a is a view of a child's cot incorporating the slide mechanismdepicted in FIGS. 1 and 2 with the addition of a foot operated latchingmechanism;

FIG. 3 b is an enlarged view of the lower part of the slide mechanismand latching mechanism of FIG. 3 a;

FIG. 4 is a perspective view of a portion of a child's cot comprisingthe mechanism and showing a further latching mechanism that is suitablefor use with the present invention;

FIG. 5 is a further perspective view of the child's cot of FIG. 4, shownwith the sliding side in the fully lowered position;

FIG. 6 shows the child's cot of FIG. 4 depicted from underneath to showthe mechanism of the present invention in three different positions; and

FIG. 7 shows a further view of the child's cot of FIG. 4 which is partlycut-away to show the mechanism of the invention in greater detail.

FIG. 1

FIG. 1 is a side view of a portion of a child's cot with the slidingside (1) in the fully raised position with one edge abutting the frameof the cot headboard (2). The cot incorporates two slide mechanismsaccording to the present invention, one at either end of the slidingside, however only one of the slide mechanisms can be seen in this view.The edge of the sliding side has also been cut away to better show theslide mechanism—in use the mechanism would be mostly enclosed within thesliding side.

The fixed slide rail (3) is attached to the headboard (2) and is in 2parts (3 a, 3 b). The rebate (4) located in the lower part of thesliding side (1) in this view the sliding side rests on the upper end ofthe lower part of the slide rail (3 a), pushed out of engagement withthe slide rail by first biasing means (not shown). The second biasingmeans (5) comprises a gas strut, the lower end of which rests on abracket (6) attached to the headboard (2). The upper end of the gasstrut is attached to the upper portion (7) of the slidable member (1).

FIG. 2

FIG. 2 is an enlarged view of part of the slide mechanism depicted inFIG. 1 showing the

-   -   sliding side (1)    -   fixed slide rail (3) having 2 parts (3 a, 3 b)    -   rebate (4)

FIG. 3

FIG. 3 a is a view of a child's cot incorporating the slide mechanismdepicted in FIGS. 1 and 2 with the addition of a foot operated latchingmechanism. FIG. 3 b is an enlarged view of the lower part of the slidemechanism depicted in FIG. 3 a. The latch comprises a footplate (5),attached to an actuating rod (6) located on the underside of the slidingside (1). In this view the actuating rod (6) is engaging a plate (7)which blocks movement of the sliding side along the slide rail. Thismaintains the sliding side in the fully lowered position countering anyforce exerted by the second biasing means (not shown). Downward pressureexerted on the footplate (5) rotates the actuating rod (6) out ofengagement with retaining means. The force exerted by the second biasingmeans may then allow the sliding side to slowly rise vertically until itreaches the fully raised position.

FIG. 4

FIG. 4 is a perspective, view of a child's cot comprising a furtherembodiment of the sliding mechanism of the present invention. Part ofthe drawing is cut-away and enlarged to show detail. Specifically, thecot comprises a sliding side (10) shown in the fully raised positionwith one edge abutting the frame of the cot headboard (12). The cotincorporates two slide mechanisms according to the present invention,one at either end of the sliding side, however only one part of one theslide mechanisms can be seen (and is enlarged) in this view.

The fixed slide rail (13) is attached to the headboard (12) and ispositioned outside the inner face of the sliding member (1). The opening(14) can be seen in the lower part of the sliding side (10) which allowsfor ingress and egress of the interlocking components on the headboard(23) and (24). In this embodiment the latching mechanism comprises apawl (15) that is actuated by a manual push-bar (17). In this view thepawl (15) is located at the upper end of the slide rail (13). In thisposition the pawl (15) prevents the sliding member (1) from moving in adownward direction because of interference with the upper face of theslide rail (13),

FIG. 5

FIG. 5 is a further perspective view of the child's cot of FIG. 4, shownwith the sliding side in the fully lowered position. Part of the drawingis enlarged to show detail. In this view the pawl (15) of the latchingmechanism is located at the lower end of the slide rail (13) and in thisposition the pawl prevents the slidable member (1) from moving in anupward direction along the slide rail (13). Pressure on the manual pushbar (17) against a leaf spring (18) or any other biasing means known inthe art (such as compression spring polymer/elastomer spring, hair pinspring) can be used to move the pawl from this position.

FIG. 6

FIG. 6 shows the child's cot of FIG. 4 depicted from underneath to showthe mechanism of the present invention in three different positions(FIG. 6( a), 6(b) and 6(c)).

FIG. 6( a) depicts the configuration of the mechanism when the slidingmember is in the fully raised position, the pawl being located adjacentthe top end of the slide rail and against a stop (13). In this positionthe pawl prevents lowering of the sliding member.

FIG. 6( b) depicts the configuration of the mechanism when the push-bar(17) has been manually depressed, opposing the leaf spring (not shown),causing the pawl (15) to rotate in the direction of the curved arrow andout of engagement with the top of the slide rail and the stop (13). Therebate is thus free to move downwards along the slide rail (13) untilthe sliding member is in the fully lowered position.

FIG. 6( c) depicts the configuration of the mechanism when manualpressure on the push-bar has been released, the leaf spring (not shown)imposing force in the direction of the arrow. The pawl (15) thus returnsto the position depicted in FIG. 6( a) but this time the pawl is locatedadjacent the lower end of the slide rail and under the stop (13). Inthis position the pawl prevents raising of the sliding member.

FIG. 7

FIG. 7 is a further perspective view of the child's cot of FIG. 4. Inthis view the sliding side (15) in the fully raised position. The cotincorporates two slide mechanisms according to the present invention,one at either end of the sliding side. In this view the ends of thesliding side are cut away to better show the slide mechanisms.

The second biasing means (21 a, 21 b) comprises gas struts; the lowerend of one of the struts is shown resting on a bracket (23). The upperend of the gas strut is attached to the upper portion of the slidablemember (15). The rebate (14) can be seen located in the lower part ofthe sliding member (15). The interlocking component (24) in thisembodiment comprises a freely rotating wheel which engages the return onthe rebate the purpose of which is to prevent the separation of thesliding member (1) from the headboard (2) and to maintain the designedgaps and running clearances. In this view the slidable member (15) restson the upper end of the lower part of the slide rail (13), pushed out ofengagement with the slide rail by first biasing means (not shown).

The word ‘comprising’ and forms of the word ‘comprising’ as used in thisdescription and in the claims does not limit the invention claimed toexclude any variants or additions.

Modifications and improvements to the invention will be readily apparentto those skilled in the art. Such modifications and improvements areintended to be within the scope of this invention.

1. A slide mechanism for a piece of furniture having a slidable member,the slide mechanism comprising: (a) a fixed slide rail; (b) a rebatewhich in use receives the fixed slide rail; (c) a first biasing means toresist engagement of the fixed slide rail with the rebate; and (d) asecond biasing means to resist freefall of the slidable member; whereinin use the slidable member is moved from a first, fully raised positionto a second, fully lowered position by exerting force on the firstbiasing means such that the slide rail is brought into engagement withthe rebate, subsequent vertical movement of the slidable member beingcounterbalanced by the second biasing means.
 2. A slide mechanismaccording to claim 1 wherein the piece of furniture is chosen from thegroup comprising cots, cribs and beds.
 3. A slide mechanism according toclaim 1 wherein the biasing means are chosen from the group comprisingcoil springs, spiral balance tubes, and gas struts or combinationsthereof.
 4. A slide mechanism according to claim 1 wherein in use, forcemust be exerted on the first biasing means in a direction generallyperpendicular to the plane of the slidable member such that the sliderail is brought into engagement with the rebate.
 5. A slide mechanismaccording to claim 1 wherein the second biasing means counterbalancesthe effect of gravity on the slidable member.
 6. A slide mechanismaccording to claim 1 wherein in use, the first and second biasing meansand the rebate are concealed from sight within the slidable member.
 7. Aslide mechanism according to claim 6 wherein in addition, the slide railis concealed from sight within the slidable member.
 8. A slide mechanismaccording to claim 1 further comprising a latching mechanism such thatthe slidable member may be latched in the fully raised position.
 9. Aslide mechanism according to claim 1 further comprising a latchingmechanism such that the slidable member may be latched in the fullylowered position.
 10. A slide mechanism according to claim 1 whichfurther comprises a latching mechanism chosen from the group comprisingmanual latches and automatic latches.
 11. A slide mechanism according toclaim 1 which further comprises a latching mechanism having a pawl whichmay be moved into engagement with the end of the fixed slide rail toprevent vertical movement of the slidable member.
 12. A slide mechanismaccording to claim 1 which further comprises a latching mechanism havinga pawl which may be moved into engagement with a stop on the furnitureto prevent vertical movement of the slidable member.
 13. A method ofoperating that slide mechanism of claim 1 the method comprising thesteps of: (a) exerting force in a direction generally perpendicular tothe plane of the slidable member such that the first biasing means isopposed and the slide rail is brought into engagement with the rebate,and (b) moving the slidable member to descend from the fully raisedposition to the fully lowered position, the second biasing meansresisting freefall of the slidable member.